Multiplicity change of required attribute

Breadcrumb

In the DATEX-Tool, it is not possible to restrict the multiplicity of an attribute, which is mandatory (at least I suppose this is the point). Example: 'accidentType' has multiplicity 1:*. It is not possible to change it to 1:1, which should be possible according to the rules. The Tool does not accept the value 1 - it does block any further action in this case, until the 1 is deleted again. Note: This problem differs from the one described just before.